Physical modeling of thrusting structure zonation in front of an intracontinental orogen

Existing experimental models do not simulate complete deformation zones, and do not totally match with the background of the composite intracontinental thrust belt in China. This work simulated the zonal characteristics in thrust structures and the reverse fault evolution in the transitional zone by building a "compression-collision" model which has rheological heterogeneity in vertical and horizontal directions. The geometric analysis shows that the improved model can simulate the complete deformation zones. The order is thick-skinned zone, transitional zone and thin-skinned zone from hinterland to foreland, which correspond to the orogen, thrust belt and basin, respectively. Moreover, fault development in the experimental model corresponds well with the geolo-gical model. The Kinematic analysis shows that the development of reverse faults in the transitional zone has gone through three stages:brittle deformation, ductile-brittle deformation and ductile deformation, but the evolution of thrust faults varies with the presence or absence of a detachment layer. Besides, the small initial fracture angle and short evolution time are the controls for the formation of thrust belts in which the dip angle of the front thrust fault is less than that of the back one.